Electric lamp sealing apparatus



Aug. 26, 1958 w. P. SCHOENOFF ETAL 2,848,843 I ELECTRIC LAMP SEALING APPARATUS 2 SheetsSheet '1 Filed March 1 5L956 lnve n tor's Waldemav P Schoeno F F,

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United States Patent O ELncrnrc LAMP SEALING APPARATU Waldemar P. Schoenofi, Euclid, and Paul Vargo, Lyndhurst, Ohio, assignors to General Electric Company, a corporation of New York Application March 1, 1956, Serial No. 568,729

6 Claims. (Cl. 49-2) Our invention relates in general to apparatus for making electric lamps, and more particularly lamps of the sealed beam type such as disclosed in U. S. Patent 2,148,- 314, issued February 21, 1939 to D. K. Wright and assigned to the assignee of the present invention.

Electric lamps of the type disclosed in the above-mentioned Wright patent comprise an accurately formed pressed glass reflector section which supports a concentrated filament or other light source accurately located with respect to the interior surface of the reflector section, the said interior surface being accurately formed to a very definite optical shape, usually paraboloidal, and having a reflecting coating thereon adapted to re-direct the light from the filament in a definite manner. Across the mouth opening of the reflector section, which has the general shape of a cup and constitutes one portion of the lamp bulb, is sealed another pressed glass cover or lens section, conventionally of dished form, constituting the other portion of the bulb and usually provided with light refracting media such as flutes and prisms, for concentrating or diffusing the light in a definite manner. The

sealing together of the two glass sections is effected at their peripheral edges which are provided for this purpose with cooperating annular sealing surfaces.

For certain applications, as where the lamp is to be employed as a vehicle headlamp, it has been proposed to provide the lamp with one or more accurately located reference shoulders or surfaces on the exterior of the lens section adjacent the peripheral seal portion thereof, which reference surfaces are adapted to be engaged by a mechanical aiming device for the purpose of properly aiming the lamp when installed in place on a vehicle. These reference surfaces, which may be constituted by the tops of three or more bosses or lugs on the lens section located immediately inwardof the sealing flange thereof at widely spaced points therearound, are accurately located in a plane bearing a definite transverse relation to the axial center line of the lamp as well as to the axis of the reflecting surface of the lamp. Since the reflecting surface and the mounting of the filament or filaments in lamps of the above-mentioned type are customarily made with great accuracy, the provision of such external reference surfaces on the lamp lens accurately located in definite predetermined planar relation to the axial center line of the lamp and to the optical axis of the reflecting surface, therefore affords a ready means for mechanically aiming the lamp while mounted in place on the vehicle inasmuch as the said reference surfaces then bear, in turn, a definite predetermined relation to the light beam projected by the lamp.

The manufacture of such type sealed beam lamps provided with lamp-aiming bosses or lugs such as described above is preferably accomplished by the method disclosed and claimed in co-pending application Serial No. 568,795 filed March 1, 1956 of GE. Meese and assigned 2,848,843 Patented Aug. 26, 1958 ice to the assignee of the present invention. 1 In this method the lens or cover glass sections as initially pressed are formed with reference surfaces on the outward side of the lens, located immediately inward of the sealing flange thereof at widely spaced points therearound and disposed in predetermined transverse relation, e. g., normal, to the axial center line of the lens, and the said reference surfaces are then accurately positioned in a predetermined transverse plane relative to the axial center line and optical axis of the lamp during the sealing together of the lens and reflector sections thereof. The reference surfaces on the lens may be constituted by the tops of three or more lamp-aiming bosses on the lens, located at widely-spaced points therearound, and the location of such reference surfaces in the said predetermined transverse plane relative to both the axial center line and optical axis of the lamp, during the sealing of the lens and reflector sections, is accomplished by displacing the lens and reflector sections axially away from each other to stretch and work the plastic glass at the seal therebetween and at the same time controlling or limiting the extent of the axial displacement of the peripheral portions of the lens section relative to the reflector section, at the region of the said reference surfaces, through the engagement of the reference surfaces with limiting stop surface means accurately located in the said predetermined transverse plane relative to both the axial center line and optical axis of the lamp.

It is an object of our invention, therefore, to provide apparatus for producing the envelope or bulb of an electric lamp of the above described character having lamp-aiming reference surfaces on the cover glass section of the lamp envelope accurately located in predetermined relation to both the axial center line and optical axis of the lamp envelope.

Another object of our invention is to provide apparatus for sealing together the glass cover and reflector sections of an electric lamp in accordance with the method as described above to produce a sealed beam type lamp having reference surfaces on the cover glass section thereof accurately located in predetermined relation to both the axial center line and optical axis of the lamp.

Briefly stated, in accordance with one aspect of the invention, a sealing machine of the indexing carrier type such as conventionally employed to seal together the lens and reflector sections of a sealed beam type lamp is provided, at one of the work stations thereof, with a vertically movable stop member supported in a position overlying the lamp in the lamp holder at said station and having downwardly facing stop surface means adapted, during the customary blow-up of the lens section to stretch and work the still plastic glass at the rim seal between the lens and reflector sections, to engage lampaiming reference surface means on the lens section, located around the periphery thereof immediately inward of the rim seal, for the purpose of limiting the amount of upward displacement of the lens section and locating the said lamp-aiming reference surface means in predetermined spacial and planar relation to the lamp seating surfaces on the reflector section. According to a further aspect of the invention, the stop member is supported for limited rocking movement and is provided with abutment means which, on downward movement of the stop member to its operative position, engage with the lamp holder to accurately locate the stop surface means on the stop member in the said predetermined spacial and planar relation to the lamp seating surface of the lamp holder.

Further objects and advantages of the invention will appear from the following detailed description of a species thereof and from the accompanying drawings.

. In the drawings, Fig. 1 is a diagrammatic plan view of a lamp sealing machineicomprising our invention.

Fig. 2 is a vertical section through the turret of the sealing'machineon the line'2.2 of Fig. l;-

Fig; '3 is a fragmentary side elevation'of the seal reshaping means of the lamp sealing machine.

Fig. 4 is a plan view of the front side of the glass lens for use in the sealing apparatus comprising our invention.

V Fig. is a section on the line 55 of Fig. 4, and

Fig. 6 is a plan view of the rear or outer side of a conventional type glass reflector section for use in the sealing apparatus comprising our invention.

Referring'to the drawings, the apparatus there shown is similar to that described and claimed in U. S. Patents 2,237,186, issued April 1, 1941 to'F. J. Malloy, and

2,334,123, issued November 9, 1943, to F. C. Perkins, and comprises a' carrier or'turret 1 provided around its periphery with a plurality of rotatable heads 2 for supporting and carrying the glass reflector sections 3 which are to be individually sealed to a cover glass or lens section 4 toform the envelope or bulb of the lamp. The heads 2 are adapted to support the glass reflectorsections 3 in an uprightposition with their concave reflecting surfaces 5 facing upwardly. The turret 1 is rotatively mounted on a vertical center shaft or column 6 and his intermittently indexed about the shaft 6 by suitable indexing means (not shown) of conventional type to carry the assembled reflector and lens sections 3 and 4 in each head 2 progressively to a succession of work stations- A-Q where various operations are performed on thesaidassembled sections. v

As shown in Fig. 2, each head 2 comprises a ringshaped main lamp holder 7 having a lamp seating rim 8 at its upper end provided with a flat upper seating surface 9 on which the seating surfaces 10 of lamp orienting bosses 11 on the reflector section 3 are adapted to rest to thereby support the reflector section in the head. The holder 7 is mounted on an upperbracket 12 supported by standards or posts 13 extending upwardly from a lower bracket 14, having a depending sleeve 15. The said sleeve 15 extends through and is rotatively mounted in a bearing 16 on the turret 1, a ball bearing 17 being interposed between the underside of the bracket 14- and the upper end ofthe turret bearing 16 to thereby support, and permit free and easy rotation of the head 2 on the turret. The heads 2 are rotated, at each station around the machine except the loading and unloading stations A and Q, and the seal-stretching or lens blowup station K,-by means of a pulley 18 fastened to the lower end of the sleeve 15 and engaged by a moving belt .as indicated in dotted lines at 19 in Fig. 2.

the spindle 20 is closed ofi at its lower end except for the passageway through the inner sleeve 26. At its lower end the inner sleeve 26 is provided with a shoe 27 which, during rotation of the turret land consequent movement of the respective heads 2 in a circular path around the machine, rides on .the upper surface of a cam track 28 extending circularly around the machine and supported from a stationary part of the machine. The shoe 27 is provided with an aperture 29 extending therethrough from its under surface and communicating with the hollow interior of the spindle 20 and inner sleeve 26. 7 When the head 2 is'positioned at different stations around the machine, the aperture 29in the shoe 27 aligns with different ports in the cam track28 at such stations,

such as indicated at 30 in Fig. 2, different ones of said ports being connected to a source of inert or reducing gas for lamp flushing purposes, to a source of vacuum,

or to a source of inert or reducing gas under pressure, de-

pending upon the particular operation which is to take place at each station.

At the first or loading station A of the machine, a

reflector section 3 and a lens or cover glass section 4, properly assembled in sealing relation .to one another with their peripheral sealing flanges 31 and 32, respec-' tively, in abutting relation to one another, are'plac'ed'on and properly mounted in'the secondary holder 21 of the head 2 at the ,said station A so as to rotate with the head, the said holder 21 being in an'elevated position relative to the ring-shaped main holder 7 at such time be cause of the engagement of the shoe 27 at the lower end of the spindle 20 with an elevated portion 33 of the cam track 28. The turret 1 then indexes the head 2 with the assembled reflector and cover glass sections 3 and 4 thereon progressively through stations B, C, and D where the glass sections, While rotating, are successively preheated by gas flames (not shown) and an inertgas, such as nitrogen, introduced through ports (not shown) in the cam track 28 and through the inner sleeve 26 and metal tube 24 into the space enclosed by the reflector and cover glass sections'to flush the saidspace and protect the reflecting coating 5 on the interior of the reflector section from the oxidizing efiect of the atmosphere. During the movement of the head 2 through the said stations 13, C, and D, the secondary holder 21 supporting the assembled reflector and cover glass sections 3, 4 is continuously maintained in an elevated position by' the engagement of shoe 27 with the said elevated portion 33 of the cam track 28 to thereby position thejreflector section 3 above and clear of the ring-shaped holder 7 so as to enable the preheating of said section by gas flamesdirected thereagainst.

Following the preheating of the assembled reflector and cover glass sections 3, 4 at stations B, C and D, the head 2 supporting the said glass sections is then successively. indexed through stations E, F, G, H and I where the sealing flanges or rims 31 and 32 of the glass sections are progressively heated and fused together by gas fires from pairs of diametrically opposite burners 34 (Fig. l) which are moved down into operative relation after the head 2 is positioned at 'eachofsaid stations. In the course of movement of the head 2 from stations D to E, the shoe relative rotation between the holder 21 and the reflector 27 on the lower end of spindle 20 passes down an inclined portion 35 of cam track 28 to a depressed portion 36 thereof, causing the said spindle and the secondary holder 21 to be lowered just enough to permit the seating bosses 11 on the sealing flange 31 of the reflector section 3 to engage and rest on the seating surface 9 of the main holder 7 so that the glass sections 3, 4 are then supported and definitely positioned thereby. This positioning of the glass sections 3, 4 on the main holder 7 then continues throughout the movement of the head 2 through stations E to K inclusive, the cam track 28 remaining at a depressed level throughout the said movement of the head.

During the fusing and'sealingpoperation, a vacuum; is

created in thespaceenclosed by' the assembled reflector and lens sections 3, 4 as soon as the sealing flanges 31, 32 of both said sections become sufiiciently plastic to be fused together, which condition ordinarily first develops at station G. The vacuum pulls or draws the two glass sections tightly together at all points around the circumference of the glass sections and across the entire width of their sealing surfaces, regardless of any war-page in the glass, thereby insuring the intimate contact of the sealing surfaces which is essential to a strong and tight seal between the glass parts. A vacuum of from one to three inches of mercury has been found to be ample to .ccornplish the desired object of pulling or drawing the tWo glass sections 3, 4 together with suflicient force to press the sealing surfaces thereof into the intimate contact necessary for a strong seal thereoetween. The evacuation of the space Within the assembled glass sections 3 and 4, is first effected at station G, where the sealing flanges 31, 32 of both sections first become sufficiently plastic to 'be fused together, and then is continued at the next succeeding station H. The evacuation is accomplished through the metal tube 24, the inner sleeve 26 and the opening 29 in shoe 27, which opening aligns with vacuum ports (not shown) in the cam tracx 28 when the head 2 is successively positioned at stations G and H, the said ports being connected to a source of vacuum (not shown). The comparative close fit between the metal tube 24 and the exhaust tube 25 of the reflector section 3 sufiiciently closes off the space Within the glass enclosure formed by the sealed reflector and lense sections 3, 4 from the surrounding atmosphere to enable the desired degree of vacuum to be obtained within the glass enclosure.

After the fusion of the sealing flanges 31, 32 of the glass sections 3, 4 and the evacuation of the glass enclosure or envelope at stations G and H, the head 2 is indexed to station I where the said sealing flanges are additionally heated to further soften the glass and complete the fusion and sealing together of the sealing flanges. Also, the positioning of the sealed glass envelope at station 1 provides a time interval for permitting the interior Space of the glass envelope, which is again connected to a source of inert gas at such station through a port (not shown) in the cam track 28, to again become filled with such gas up to atmospheric pressure or nearly so.

In addition to the heating of the sealing flanges 31, 32 of the glass sections 3, 4 at station I, the peripheral edges or rims of the said sealing flanges are also engaged at said station by a pair of diametrically opposite forming rollers 37 (Fig. 3) which press against the said peripheral edges of the sealing flanges to thereby form or shape the same and further promote the fusion and sealing together of the sealing flanges. While the rolling of the edges of the sealing flanges 3f, 32 is preferably performed at station I, this operation may be etfected instead at either one of the two preceding stations G and H or at any two or even at all three of the stations G, H and l by the provision at such stations of such forming rollers similar to the rollers 37.

From station I, the head 2 is then indexed to station K where the sealed reflector and lens sections 3, 4 are axially, i. e. vertically, displaced a limited distance away from each other and through the required distances at the region of each of a plurality of aiming bosses or pads 38 (Fig. 4), located on the exterior of the lens section 4 at widely spaced points therearound and immediately inward of its sealing flange 32, to accurately locate the top surfaces 39 of each boss 38 a predetermined, e. g. a uniform, vertical distance above the plane of the seating surfaces of the lamp orienting bosses 11 on the reflector section 3. This axial displacement of the reflector and lens sections 3, 4 at the same time serves to stretch and work the still plastic glass at the seal between the two glass sections, thereby partially relieving the glass seal of internal strains. By so locating the top surfaces 39 of the aiming bosses 38 on the lens section 4 uniformly at the same distance axially of the lamp envelope from the plane of the seating surfaces 10 on the reflector section 3, which plane occupies a predetermined transverse relation to the optical axis of the reflector section 3, the top surfaces 39 of the aiming bosses 38 will, in turn, be disposed in a corresponding plane bearing the same predetermined transverse relation to the said optical axis as that occupied by the plane of the seating boss surfaces 10 of the reflector section.

The axial displacement of the reflector and lens sections 3 and 4 at station K is preferably accomplished by introducing inert or reducing gas under pressure into the sealed glass envelope through the metal tube 24, inner sleeve 26 and the opening 29 in shoe 27, which opening aligns with the cam track port 30 when the head 2 is positioned at station K, the said port 30 being connected by pipe 49 to a source of inert or reducing gas. The inert gas entering the space within the sealed glass sections 3, 4 causes an upward movement of the lens section 4 relative to the reflector section 3 around the annular extent of the seal therebetween, thereby stretching and working the still plastic glass at the seal.

In accordance with the invention, suitable lens displacement control means 41 are provided at station K for limiting and accurately controlling the amount of the upward axial movement or raising of the lens section 4 relative to the reflector section 3. As shown in Fig. 2, the said displacement control means 41 comprises a stop member 42 overlying the main holder 7 and the lamp envelope at station K and provided with a depending annular flange or collar 43 having a flat undersurface 44 disposed approximately in a horizontal plane and adapted to engage the top surfaces 39 of the aiming bosses 38 on the lens section 4. The stop member 42 is carried by a support arm 45 overhanging the periphery of the turret 1 and fastened to the upper end of a vertically extending operating rod 46. The operating rod 46 is mounted for vertical reciprocating movement in a support or bearing 47 fastened on a bracket 48 secured to a stationary part (not shown) of the machine frame. The operating rod 46 is vertically reciprocated by suitable actuating means (not shown) operating in timed relation to the index movements of the turret 1, e. g., operated from the main cam shaft of the machine, to carry the stop member 42 and associated parts from an elevated inoperative position clear of the path of movement of the lamp envelope and the associated head 2 to and away from the station K, to a lowered operative position (as shown in Fig. 2) as determined by the engagement of the lower ends of three or more stop pins 49 depending from the stop member 42 with the upper surface 56 of an outwardly extending stop flange or ledge 51 on the main holder ring 7 of the head 2. The group of stop pins 49 are located on the stop member 42 outwardly of and spaced more or less equally around and concentric with the annular stop flange 43 thereon so as to just clear the outer periphery 52 of the seating rim 3 on the lamp holder ring 7 when the stop member is vertically aligned therewith and located in its lowered operative position. As shown, the stop pins 49 are longitudinally or vertically adjustable in the stop member 42, as by having a screw-thread engagement therewith and locked in adjusted position by lock nut 53, and they are so adjusted in the stop member as to locate the annular stop surface-44 of the stop member 42 in the desired pre determined relation, e. g. parallel relation, to the annular seating surface 9 of the holder ring 7 and spaced a predetermined distance therefrom when the stop member 42 is in its lowered operative position with the stop pins 49 in engagement with the annular flange 51 on the holder ring 7.

To permit the engagement of all the stop pins 49 with the stop flange 51 on the main holder ring 7 when the stop member 42 is lowered to its operative position, thereby insuring the proper planar positioning of the annular stop surface 44 of the stop member in exact predetermined relation to, e. g. parallel, with the reflector section seating surface 9 of the main holder ring 7, the'stop member 42 is supported on the support arm 45'through a suitable connection (as by meansof-a'floating connection such as illustrated at 54 in Fig. 2 )'whi'eh allows a limited amount of rocking movement of the stop member 42 and preferably, in addition, a limited amount of lateral shifting movement as well. In the case of the particular connection 54 illustrated, the stop member 42 is in eflect hung from the lower end of a hanger post55 depending from the support arm 45, the hanger post 55'for such purpose being provided with an outward annular flange 56 at its lower end which is received within a circular recess 57 in the upper side of the stop member 42. A ring-shaped cover plate 58 fastened to the upper side of the stop member 52 around the circular recess 57 overlies the annular flange 56 of the hanger post 55 to thereby hold the stop member in place on the end of the hanger post. As shown, the recess 57 in the stop member 42 is of slightly larger size (both in diameter and depth) than the flange 56 on the hanger post 55 so as to provide a limited amount of clearance therebetween suflicient to permit the desired limited amount of rocking and lateral shifting movement for the stop member 42 'on the end of the hanger post 55. The limited lateral shiftabilityof the stop member 42 afforded by the clearance in the connection 54 permits the stop member, when moved to its lowered operative position, to be vertically aligned or centered withrespect to the main holder ring 7 so as to locate the annular flange 43 of the stop member concentric with the seating surface 9 of the holder ring 7. To this end, the stop pins 49 are provided with tapered lower ends 59 which, during the downward movement of the stop member 42 to its lowered operative position, engage with the outer periphery 52 of the upper seating rim8 of the reflector section holder 7 to effect the vertical aligning of the stop member 42 with the holder ring 7. If desired, a compression coil spring 69 may be interposed and compressed between the underside of the support arm 45 and the upper side of the cover plate 58 on the stop member to yieldingly restrain rocking or upward movement of the stop member 42 relative to the hanger post 55. To lock the operating rod 46 against rotation within the bearing 47 so as to prevent swinging movement of the support arm 45 about the bearing and thereby maintain the'hanger post 55 for the stop member 42 in true vertical alignment with the holder ring 7 of eachhead 2'when positioned at station K, the operating rod 46is provided with a cross pin 61 which snugly fits and slides up and down within a vertical slot 62 in the bearing 47.

In the operation of the seal-stretching and lens blow-up mechanism at station K, as soon as the two sealed glass sections 3 and 4 are indexed to station K, the stop member 42 is lowered by the operating rod 46 and associated actuating mechanism to its lowered operative position as determined by the engagement of the stop pins 49 with the stop flange 51 on the holder ring 7. At the limit of such downward movement of the stop member 42, a switch 63, controlling the operation of a valve 64 in the inert gas supply line 40, is closed to thereby open the said valve and thus supply inert gas to the port 30. The inrush of inert gas up through the port 30, inner sleeve 26, and metal tube 24 into the interior of the sealed lamp envelope, then acts to raise or lift the lens section v4 upwardly relative to the reflector section 3. The amount of such raising or upward displacement of the lens section 4 is limited and accurately controlled,however, by the engagement of the'tops 39 of the aimingbosses 38 on the lens section with the annular stop surface 44 of the stop member. As a result, the tops 39 of the aiming bosses 38 on the lens section 4 acquire exactly the same planar relation to the seating surfaces 10 of the seating bosses 11 on thereflector section 3 as that of the stop surface 44 on the stop member relative to the reflector seating surface 9 of the holder ring 7. During the upward movement of the lens section-4 by the gas pressure introduced into the lamp envelope, the weight of the stop member 42 ordinarily issuflicient 'of itself to hold the stop member positively down in place in its lowered operative position, against the upward pressure exerted thereon by the lens section 4. However, the use of the coiled spring 60 between the stop member 42 and its support arm 45 serves to more positively assure against the stop member being lifted by and along with the lens section 4 during the upward displacement of the latter by the gas pressure created in the lamp envelope.

Following the initial blow-up or upward displacement of the lens section 4 relative to the reflector section 3 at station K to effect the precise locating of the'upper surfaces 39 of the aiming bosses 38 on the lens section in a predetermined planar, e. g. parallel, relation to the plane of the seating surfaces 10 of the seating bosses 11 on the reflector section 3, andat the same time to stretch the plastic glass seal to remove the internal strains therefrom, the gas pressure is thenmaintain'ed Within the lamp envelope for a period of time suflicient to arrow the plastic glass at the seal to cool and rigidify, thereby assuring the said predetermined planar relationship between the top surfaces 39 of the aiming bosses 38 and the seating surfaces 10 of the seating bosses 11 in the finished lamp. The stop member 42 is thereafter raised to its upper or inoperative position clear of the lamp envelope in the head 2, and the turret 1 then indexes to carry the lamp envelope successively to the succeeding stations L to Q where the lamp envelope is annealed by means of gas flamesdirected against the glass sections 3 and 4. The annealing of the lamp envelope is controlled,

however, at the successive .stations L to Q so that the lamp envelope loses heat more rapidly than it gains and the lamp envelope gradually drops in temperature until further annealing is not required when station Q is reached, which is the unloading station for the completed lamp envelopes.

Although a preferred embodiment of our invention has been disclosed, it will be understood that the invention is not to be limited to the specific construction and arrangement of parts shown, but that they may be widely modified within the spirit and scope of our invention as defined by the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for sealing a concave glass reflector section of a lamp envelope to a cover glass section having lamp-aiming surface means on itsoutward face disposed about the periphery thereof in a predetermined transverse plane relative to the axis of the cover glass section and located immediately inward of the sealing flange thereof, said apparatus comprising a ring-shaped holder for supportingsaid glass sections in assembled sealing relation with peripheral sealing flanges thereon in abutting sealing relation to one another, said holder ring being positioned with its axis vertical and having a flat horizontally disposed annular seating surface on which seating surfaces on the reflector section are adapted to rest to support the latter in place with its concave reflecting surface facing upwardly, heating means for fusing limit and control the amount of upward displacement thereof relative to the reflector section, and means vertically fixed in a predetermined position with respect to said stop means for supporting and locating said stop meansin a predetermined position relative to said holder 9 ring with the said stop surface means accurately disposed in a predetermined plane relative to the plane of the said seating surface on said holder ring.

2. Apparatus for sealing a concave glass reflector section of a lamp envelope to a cover glass section having lamp-aiming surface means on its outward face disposed about the periphery thereof in a predetermined transverse plane relative to the'axis of the cover glass section and located immediately inward of the sealing flange thereof, said apparatus comprising a ring-shaped holder for supporting said glass sections in assembled sealing relation with peripheral sealing flanges thereon in abutting sealing relation to one another, said holder ring being positioned with its axis vertical and having a flat horizontally disposed annular seating surface on which seating surfaces on the reflector section are adapted to rest to support the latter in place with its concave reflecting surface facing upwardly, heating means for fusing and sealing said sealing flanges together, means for successively connecting the interior of the envelope first to a vacuum to compress the sealing surfaces tightly together and then to a source of gas under pressure to displace the cover glass section upwardly relative to the reflector section so as to stretch and work the glass at the seal, stop means disposed above the said holder and having a downwardly facing flat annular stop surface concentric with said holder ring and adapted to engage the said lamp-aiming surface means on the cover glass section to accurately limit and control the amount of upward displacement thereof relative to the reflector section, and means for supporting and locating said stop means vertically fixed in a predetermined position with respect to said stop means in a predetermined position relative to said holder ring with the said annular stop surface accurately disposed in a predetermined plane relative to the plane of the said seating surface on said holder ring.

3. Apparatus for sealing a concave glass reflector section of a lamp envelope to a cover glass section having lamp-aiming surface means on its outward face disposed about the periphery thereof in a predetermined transverse plane relative to the axis of the cover glass section and located immediately inward of the sealing flange thereof, said apparatus comprising a ring-shaped holder for supporting said glass sections in assembled sealing relation with peripheral sealing flanges thereon in abutting sealing relation to one another, said holder ring being positioned with its axis vertical and having a flat horizontally disposed annular seating surface on which seating surfaces on the reflector section are adapted to rest to support the latter in place with its concave reflecting surface facing upwardly, heating means for fusing and sealing said sealing flanges together, means for successively connecting the interior of the envelope first to a vacuum to compress the sealing surfaces tightly together and then to a source of gas under pressure to displace the cover glass section upwardly relative to the reflector section so as to stretch and work the glass at the seal, stop means disposed above the said holder and having a downwardlyfacing flat annular stop surface concentric with said holder ring and adapted to engage the said lamp-aiming surface means on the cover glass section to accurately limit and control the amount of upward displacement thereof relative to the reflector section, means supporting said stop means and providing a limited amount of rocking movement therefor, and locating means on said stop means vertically fixed in a predetermined position with respect thereto and engageable with said holder ring to accurately locate said stop means in a predetermined position relative to said holder ring with the said annular stop surface accurately disposed in a plane parallel to and spaced a predetermined distance upwardly from the plane of the said seating surface on said holder ring.

4. Apparatus for sealing a concave glass reflector section of a lamp envelope to a cover glass section having lamp-aiming surface means on its outward face disposed about the periphery thereof in a predetermined transverse plane relative to the axis of the cover glass section and located immediately inward of the sealing flange thereof, said apparatus comprising a ring-shaped holder for the reflector and cover glass sections disposed with its axis vertical and having a flat horizontally disposed upwardly-facing annular seating surface for supporting the reflector section with its concave reflecting surface facing upwardly, heating means for fusing and sealing the sealing flanges of said glass sections together, means for connecting the interior of the envelope to a source of gas under pressure, while the glass at the seal is in a plastic condition, to displace the cover glass section upwardly relative to the reflector section so as to stretch and work the glass at the seal, a stop member disposed above said holder ring and having a flat downwardlyfacing annular stop surface adapted to engage the said lamp-aiming surface means on said cover glass section during the said upward displacement thereof, support means mounting said stop member for limited rocking and vertical movement and with its said annular stop surface approximately concentric with said holder ring, operating means connected to said support means for vertically moving the support means and associated stop member, and cooperating abutment means on said stop member and holder ring inter-engageable on downward movement of said stop member to accurately locate the latter in a predetermined position relative to said holder ring with the said annular stop surface accurately disposed in a plane parallel to and spaced a predetermined distance upwardly from the plane of the reflector seating surface on said holder ring, the said abutment means on said stop member being vertically fixed in a predetermined position with respect thereto.

5. Apparatus for sealing a concave glass reflector section of a lamp envelope to a cover glass section having lamp-aiming surface means on its outward face disposed about the periphery thereof in a predetermined transverse plane relative to the axis of the cover glass section and located immediately inward of the sealing flange thereof, said apparatus comprising a ring-shaped holder for the reflector and cover glass sections disposed with its axis vertical and having a seating rim at its upper end provided with a flat horizontally-disposed upwardly facing annular seating surface for supporting the reflector section with its concave reflecting surface facing upwardly, said holder ring also having stop flange means extending horizontally outward from the holder ring below and outwardly beyond the said seating rim thereon, heating means for fusing and sealing the sealing flanges of said glass sections together, means for connecting the interior of the envelope to a source of gas under pressure, while the glass at the seal is in a plastic condition, to displace the cover glass section upwardly relative to the reflector section so as to stretch and work the glass at the seal, a stop member disposed above said holder ring and having a flat downwardly-facing annular stop surface adapted to engage the said lamp-aiming surface means on said cover glass section during the said upward displacement thereof, support means mounting said stop member for limited rocking and vertical movement and with its said annular stop surface approximately concentric with said. holder ring, operating means connected to said support means for vertically moving the support means and associated stop member, and at least three step pins extending downwardly from said stop member at approximately equally spaced points about and located outwardly of the said annular stop surface thereon, said stop pins being vertically fixed in predetermined position with respect to said stop member and being engageable with the said stop flange on the holder ring on downward movement of the stop member to thereby accurately locate the latter in a predetermined position relative to said holder ring with the said annular stop surface accurately disposed in a plane parallel to and spaced a predetermined distance upwardly References Cited in the file of this patent UNITED STATESLPATENTS Allen Nov. 17, Donovan et al. June '21, Malloy Apr. 1, McGowan et al. Feb. 17, Perkins Nov. 9, Lyon .Q. Apr. 3, 

